Insulated door assembly with low thermal deflection

Abstract

Compression molded pigmented door skins fabricated by compression molding a pigmented, curable, unsaturated polyester sheet molding compound containing a co-curable unsaturated monomer, a low profile additive, and a microvoid-reducing thermoplastic polymer, exhibit uniform stainability while maintaining a low linear thermal coefficient of expansion. Such door skins are suitable for preparing wood grain textured exterior insulated doors which exhibit minimal thermal deflection when exposed to interior/exterior temperature differentials, even at eight foot door heights. The doors may be stained without first applying a seal coat.

What is claimed is:  
     
       1. In a process for preparing door skins and other door components by the molding of sheet molding compound comprising a curable unsaturated polyester molding resin in a heated mold under pressure, the improvement comprising: 
       selecting, as a cure catalyst composition,  
       (a) a catalyst component containing t-amylperoxybenzoate in major part relative to the total weight of the catalyst component, said catalyst component present in an amount effective to cure said sheet molding compound in said heated mold, and  
       (b) an amount of a polymerization inhibitor composition effective to substantially prevent cure of said sheet molding composition at room temperature, wherein the cure time is less than 60 seconds.  
     
     
       2. The process of  claim 1  wherein the cure time is less than 50 seconds. 
     
     
       3. The process of  claim 1  wherein a vacuum is applied upon closure of the tool in which said sheet molding compound is molded. 
     
     
       4. The process of  claim 1  wherein said vacuum is between 15 and 29 inches mercury and is released from 5 to 30 seconds after its application. 
     
     
       5. A process for reducing surface defects on a stainable compression molded SMC doorskin without creating a non-uniformly stainable surface, said process comprising: 
       a) selecting as an SMC, an unsaturated polyester-containing SMC which exhibit a cure time of one minute or less;  
       b) upon closure of a door skin mold containing said SMC, applying a vacuum of from about 10 inches Hg to 29 inches Hg; and  
       c) maintaining said vacuum for a period of from about 5 seconds to about 30 seconds.  
     
     
       6. The process of  claim 5  wherein said cure time is 50 seconds or less. 
     
     
       7. The process of  claim 5 , wherein said vacuum is from about 15 to 29 inches Hg, and the pressure of the mold is from about 200 psig to about 1500 psig. 
     
     
       8. The process of  claim 5 , wherein the vacuum is applied for from 10 to 23 seconds.